Outboard motor



Oct. 31, 1950 E. M. WILSON ETAL OUTBOARD MOTOR Filed June 11, 1946Sheets-Sheet 1 [200m /l /Z l V/z so/v, 91 1471 44/14 A 044 oc/r,

" INVENTORS ATTORNEY Oc 1950 E. M. WILSON ET AL 2,528,480

OUTBOARD MOTOR 4471/4; p 06 INVENTORS Oct. 31, 1950 E. M. WILSON ET AL2,528,480

OUTBOARD MOTOR Filed June 11, 1946 Y 5 Sheets-Sheet 5 4200/v/W. /////A50% 442 /4/14 9041. our,

INVENTORS ATTORNEY.

1950 E. M. WILSON ET AL 2,523,480

OUTBOARD MOTOR Filed June 11, 1946 5 Sheets-Sheet 4 1 -8- fZDO/VMW/LSO/V,

ZATHAM Q04; oc/r,

' INVENTORS OUTBOARD MOTOR 5 Sheets-Sheet 5 Filed June 11, 1946 w m w 1a I v. m w m 7. w w 3 w 4 p n.

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INVENTORS firroewzx Patented Oct. 31, 1950 OUTBOARD MOTOR Eldon M.Wilson, La Canada, and Latham Pollock,

Los Angeles, Calif, assignors to Southern En- Incorporated, Burbank,Calif, a corporation of California Application June 11, 1946, Serial No.675,920

.gineering Company,

7 Claims. 1

The present invention relates to outboard motors, and is directed to theprovision of a new and improved outboard motor embodying manyadvantageous features not found on any prior machine to our knowledge.

One of the principal shortcomings of outboard motors heretofore knownhas been the lack of a manually controllable clutch in the propellertransmission mechanism which could be disengaged at will to permit thepropeller to stop while the engine idles. Thus, when it has been desiredin the past to bring the boat to 'a standstill, the only course open hasbeen to kill the engine and then to restart it when ready to move on.Twocycle engines, which power the great majority of all outboard motors,are sometimes dificult to start even when hot, and frequent restartingnecessitated by the absence of a clutch is a serious inconvenience andannoyance.

The-omission of a clutch has not been due solely to lack of foresight onthe part of outboard motor designers, nor to a desire to reduce thesize, weight, and cost of the unit, but has been dictated primarily bythe difiiculties experienced in obtaining adequate cooling of the enginewhen the clutch is disengaged. This is due to the fact that all outboardmotors have heretofore been water-cooled, and the cooling water has beencirculated through the cylinder jackets by a pump submerged beneath thewater level and driven from the propeller shaft or the vertical driveshaft. Thus, when the drive shaft or propeller shaft were stopped bydisengaging the clutch, the pump stopped also and the circulation ofcooling water ceased, with resultant heating of the engine. Attempts toovercome this difficulty by driving the pump directly from the enginecrankshaft resulted in other complications and were generallyunsatisfactory.

The present invention, however, eliminates the quirements of such a unitwhen operating with the clutch disengaged.

Another object of the invention is to provide a novel clutchconstruction combining simplicity,

compactness, light weight, absolute reliability, and low cost ofmanufacture. In this connection, one of the features of our novel clutchconstruction resides in the shape and arrangement of the driver anddriven member whereby any oil seeping down into the clutch compartmentfrom the engine crankcase is thrown outward by centrifugal force fromthe driver and is prevented from coming in contact with the clutchfacings.

A further object of our invention is the provision of a novel shell oroutside casing for the engine which constitutes a volute housing for theblower fan, In this way, the outside casing of the engine serves theseveral functions of providing an ornamental and protective covering fortheentire power unit; providing a volute housing of high efliciency forthe centrifugal blower; and providing a shroud for directing the coolingair from the blower down over the cylinders. By thus eliminating aseparate blower housing and cylinder shroud in addition to the'usualprotective casing the bulk of the outboard motor is reduced to aminimum, resulting in a compact unit of pleasing appearance and lightweight.

These and other objects and advantages of the present invention willbecome apparent to those skilled in the art upon consideration of thefollowing detailed description of the preferred embodiment thereof,reference being had to the appended drawings wherein Figure 1 is a topplan view of an outboard motor embodying the principles of ourinvention;

Figure 2 is a partially sectioned side-elevational View of the same;

Figure 3 is an enlarged sectional view of the power head and clutchmechanism;

Figure 4 is a still further enlarged fragmentary view of Figure 3,showing the clutch in disengaged condition; s

Figure 5 is a sectional view, taken along the line 55 in Figure 4,showing the preferred arrangement of Y the eccentric wheel, whichactuates the clutch;

Figure 6 is a similar view of an alternative arrangement of theeccentric wheel and rollers, which provides positive engagement of theclutch and eliminates the need for a clutch spring;

Figure '7 is a partially sectioned side elevational view of theconstruction shown in Figure 6;

Figure 8 is a sectional view, drawn to enlarged. scale and taken alongthe line 88 in Figure 3,

showing the construction of the cooling-air fan 1 chamber;

Figure 9 is a partially sectioned side elevational ders.

'plane'bya plurality of bolts, not shown. blower is of the centrifugaltype and comrim and said flange.

view of the outboard motor turned 180 around to drive the boat inreverse, illustrating the maner in which the anti-tilt lock plunger iscammed down behind a pin bolt on the transom bracket to prevent themotor from being tilted; and

Figure is a vertical section taken through an alternative embodiment ofthe clutch mechanism.

Reference is had now to the drawings, wherein the reference numeral Itdesignates the power head of the outboard motor in its entirety, saidpower head including the motor H with its related accessories such asthe carburetor, magneto, fuel tanks, and starter. The lower unit isindicated at E3, and comprises a shaft housing i l enclosing the driveshaft l5, clutch l6, gears ll, and propeller IS. The outboard motor isadapted' to be mounted on the transom of a boat by means of a transombracket 22, and is steered by a tiller bar 24 which is fixed to the topend of the shaft housing l4 and extends forwardly therefrom.

In the preferred embodiment of our invention, the motor ll takes theform of a two-cylinder, two-cycle, air-cooled engine, having acrankshaft 26 disposed vertically and the cylinders Z'i arranged inline, to the rear of the crankshaft. The two cylinders and the top half28 of the crank case- (or rear half as it appears in the drawings) arepreferably cast en bloc, and a separate pan or bottom crankcase portion29 is bolted to the top half 28. A' carburetor 38 is mounted on thefront end of the bottom crankcase'portion 29 as shown, and the fuel-airmixture from the carburetor is drawn into a manifold. chamber 3% andthence through reed valves 32 into separate crankcase compartments 33and 34 by the pumping action of the pistons, as is well understood inthe art. The crankshaft is journaled in top, center, and bottom bearings35, 35' and 31, respectively, said center bearing being supported in asolid partition as which divides the crankcase into thetWo'pressure-tight compartments 33, 35.

The top end of the crankshaft 26 projects above the end of the crankcaseand has a magneto rotor ll mounted thereon in the usual man ner.Thestator 3'2 of the magneto is mounted on the top end of the crankcasein any suitable fashion, and has an operating lever i3 extendingforwardly from the bottom side thereof, said lever preferably being alsoconnected to the carburetor throttle valve by suitable linkage (notshown) so that the throttle is closed simultaneously with retarding ofthe spark.

The power head H3 is enclosed by a streamlined cast metal shell 56 whichhas the dual function of protecting the operator from contact with thehot engine, while at thesame time providing a housing for the coolingair blower 5i and a shroud for directing the air down over the cylin-The shell is preferably made in two halves to facilitate coring thecasting, said halves being joined together in longitudinal vertical Theprises an annular rim '52 having a radial flange 53 extending outwardlyfrom the bottom edge thereof, with a plurality of angularly spaced,radially extending blades 5% fixed to both said The blades 54. arepreferably curved, as shown in Figure 8, which has the effect ofimproving the efficiency of the blower. An overhanging portion 55 ofeach blade projects radially inward over the top of the rim 52, and therim 52 is pressed over the outer shell of the magneto rotor at to bringthe bottom edge of said overhanging blade portions into contact with thetop of the rotor shell.

The housing for the blower 5! is in the form of a volute, and is definedin part by the shell 56 and inv part by a horizontal partition 55 castintegrally with the two halves of the shell and disposed in closelyspaced relation beneath the flange 53. The partition 56 is formed with acircular opening 5? concentric with the crankshaft 2'5, through whichthe latter projects. Also cast integrally with the left hand half of theshell 5% (the top half, as seen in Figure 8) is a vertical partition 58which is joined with the side and top of the shell and projectslaterally inward to the inner edge of the horizontal partition 55. Theleft hand portion of the horizontal partition 55 terminates in an edge59 which extends rearwardly from the opening 51 to the back end of theshell 5%, parallel to the axis of the cylinder N and offset slightly toone side thereof, as shown in Figure 8. The edge 59 of the partition 55serves to confine the cooling air to the finned cylinders 2'1, closingoff the open spaces alongside the cylinders through which the air wouldotherwise be wasted. A circular opening 258 in the partition 56 directsa portion of the air down .over the finned exhaust pipe 25i to cool thelatter. The right hand half of the partition 55 terminates rearwardly ina shelf 252, the edge of which extends rearwardly from the opening 51parallel to the opposite edge 59' to a point approximately even with thehead end of the cylinders, where it is cut off to provide an enlargedopening through which a substantial portion of the air is directed downover the finned cylinder heads.

Cooperating with the shell 50- and partition 56 is a curved verticalwall it which may be made of sheet metal and which is attached by screwsat one end 61 to the inner edge of the partition 58 and'at the other end62 to the shell 59. The wall Bil extends from the horizontal partition56 up to the bottom surface of the top wall of the shell 5t, and isshaped to conform closely to the curvature of the shell. The end 6! ofthe wall 68 lies closely adjacent to the outer periphery of the blower5|, while the opposite end 62 of the wall, diametrically across theblower, is tangent to the shell 50. The chamber thus formed between theblower wheel and the wall is substantially a volute, increasinguniformly in cross sectional area from end 6! to end 62.

Air is drawn into the blower housing through a circular intake opening55' in the top of the shell 59 concentric with the axis ofthe blower,and through a plurality of radially extending slots 57 arranged in acircle around'the opening 65, as shown in Figure 1. These slots 6'!provide the requisite cross sectional area for the intake opening, andat the same time afford a protective grill for preventing entrance ofany foreign object into the blower which might damage the same orobstruct the free passage 0f air. The opening 65 is further protected bya rope-starter wheel 16 which is bolted at 69 to the top of the magnetorotor housing ll and which is disposed slightl above the opening, saidwheel having a somewhat larger outside diameter than the intake openingso that the latter is completely sheltered under the starting wheel. Airfrom the blower 5| is discharged through the opening 66 defined by thevertical edge BI and the opposite wall of the shell 50, and is directeddown over the finned cylinders and confined thereto by the downwardlycurved rear end portion of the shell 50, being discharged to theatmosphere through an opening II in the bottom of the shell.

The blower housing construction described in the paragraphs above,utilizing the outer shell 50 of the power head for the greater part ofits wall area, provides a unit of the very minimum bulk, which is animportant consideration in outboard motors. Such motors are usuallytransported in automobile trunks and, at best, are unwieldy to handle.Furthermore, since they are usually attached to relatively small boats,a motor of excessive size presents an incongruous appearance.

In addition to the consideration of size, the volute chamberconstruction, with its uniformly increasing cross-sectional area betweenpoints 6| and 62 contributes appreciably to the overall efiiciency ofthe centrifugal blower, reducing the power required for cooling theengine.

The lower unit I3, as brought out previously, comprises a shaft housingI4 which encloses the drive shaft I5 and, at its upper end, contains aclutch I6. The shaft housing I4 is preferably die cast in fourlongitudinal sections 75, 16, TI and 18, which are joined together asshown in Figure 2.

The top section 15 of the housing is cylindrical in shape and isprovided at its upper end witha cup-shaped portion 90 of enlargeddiameter which receives an annular mounting flange portion 8| projectingaxially downward from the bottom end of the crankcase. The power head Iis secured to the top section I of the lower unit I3 by means of twobolts I9 on opposite sides of the motor which extend through alignedbolt holes in the cup-shaped portion 80 and in the crankcase. The hollowinterior of the housing section I5 is divided by a partition 62 to forman upper compartment 83 which is separate from the balance of theinterior of the shaft housing. In the bottom portion of the partition 82is a sleeve bearing 84 within which the drive shaft I5 is journaled. Theshaft I5 is also journaled adjacent its bottom end in a second sleevebearing 85 (see Figure *2) which is supported by a horizontal partition86. The gears I! are contained within a compartment 90 formed bycompanionate cavities in sections TI and I8, and comprise a beveledpinion 9| fixed to the bottom end of shaft I5 which meshes with abeveled gear 92 mounted on and pinned to the horizontally disposedpropeller shaft 93. The shaft 93 is journaled in bearings 94 and 95 andprojects rearwardly from its housing, the propeller I8 being mountedthereon in the usual manner.

The shaft housing I4 also serves as an exhaust pipe through which theexhaust gases from the engine are carried for under-water discharge, andto this end, the top section is provided on its back side with a port 98which communicates with the open interior of the housing. The exhaustpipe I of the engine is bolted to said port, andthe exhaust gases arecarried down through the hollow shaft housing and discharged beneath thewater through a flattened tail pipe I00 projecting rearwardly from thehousing below the anti-cavitation plate IOI and in closely spacedrelation thereto.

The drive shaft I 5 is arranged coaxial with the crankshaft 26 of theengine and is adapted to be connected thereto by the clutch mechanism I6which will now be described.

In its preferred form, illustrated in Figures 3 and 4, the clutch I6comprises a driver I05 and driven member I06, the driver I05 being inthe form of an inverted cup having a sunken center, and the drivenmember I06 being disposed beneath the driver and within the confines ofthe outer wall thereof. The driver 05 is bolted to the bottom side of acoupling member II9 having an upwardly extending fiat tongue I I I whichis slidably and non-rotatably disposed within a correspondingly shapedhole I01 in the end of the crankshaft. This construction provides adriving connection between the crankshaft andfclutch driver whichprevents the transmission of end thrust forces from either member to theother, and also provides a quickly separable coupling permitting thepower head I0 to be lifted off of the lower unit when the two mountingbolts 19 are removed. The hub of the clutch driver I05 has a centralbore I I2 into which the outer race II3 of a ball bearing H4 is pressed.The top edge of the outer race II 3 abuts against the bottom surface ofmember I I, while the bottom edge of the race is engaged by an inwardlyturned flange II5 on the driver hub. The inner race, designated at H6,is pressed onto a stub portion E20 Of reduced diameter at the end of theshaft I5, the bottom endof said race abutting against a shoulder IZI onthe shaft, while the top end is engaged by a retainer ring.

The downwardly turned outer flange I22 of the driver 505 is conical inshape and is engaged on its inner face by a clutch facing I23 ofcorresponding conical shape which is secured by countersunk screws H9 tothe outer periphery of the driven member I655. The driven member I06 isformed with a hub I25 having a square hole I26 broached through thecenter thereof which receives a portion I of square cross section on theshaft I5. By virtue of this construction, the driven member I06 isslidable axially along the shaft but is held against rotation withrespect thereto. The driven member is yieldingly urged into engagementwith the driver by means of a spring I 3I which embraces the shaft I5and bears against the bottom end of the hub I25. The bottom end of thespring i3I bears against a thrust washer I32 which is welded to theshaft I5 just above the bearing 24.

The advantages of the clutch construction described are many. Probablythe most important of these advantages is the way in which the clutchfacing is protected from oil which unavoidably seeps down through thebottom bearing 31 of the engine from the crankcase. Such oil drops intothe cavity I33 in the top of the member H0 and is thrown outwardly bycentrifugal force to the inside surface of the mounting flange 8| whereit runs down into the compartment 83 and collects in the bottom thereof.The clutch driven member I05, being enclosed on the top and sides by thedriver 505, is completely sheltered from any oil and enjoys completeprotection therefrom. The oil then seeps through the clearances of theshaft bearing 84 to lubricate the latter and is-expelled through thetailpipe I99 with the exhaust. The partition 82 prevents the entrance ofexhaust gas into the compartment 83 where it would foul the clutchfacings and escape through the opening MI.

Another advantage of our improved clutch lies in the arrangement of theclutch spring I3I, thrust washer I32, driven member I 536, driver I 05,andball bearing IM, whereby the thrust of the spring is taken in bothdirections by the drive the driven member.

comes to a stop as soon as the clutch is disenshaft I5. By reason ofthis construction, the thrust of the spring I3I is isolated from theengine crankshaft, preventing undue wear on the thrust faces of thecrankshaft main bearings.

Another advantageous'feature of the clutch described resides in the factthat disengagement of the clutch is accomplished by pulling the drivenmember E89 down out of contact with the driver, and this is done by ashift lever I49 (to be described in more detail presently) which engagesSince the driven member gaged, it will be seen that there is no runningfriction between the shift lever M9 and the driven member I86 while theclutch is disengaged, which is a distinct advantage inasmuch as iteliminates the need for a special throw-out bearing which is necessaryin the more widely used multiple disk clutch,'or in other clutchconstructions wherein the shifting lever acts on the constantly rotatingdriver.

The clutch I6 is disengaged by means of the shift lever M9 which extendsthrough an opening MI in the front wall of the shaft housing top sectionI5, and is pivotally mounted on a pin M2 for swinging movement in avertical plane. The inner end of the lever I58 is bifurcated to form afork I43, the fingers of which are disposed within a groove I44 in thehub I on opposite sides thereof. Pressed into a longitudinally extendinghole I45, drilled in the outer end of lever arm I49, is a pin I46uponwhich is journa-lled eccentric I5Il. The outer rim of the eccentricI59 rides on a pair of laterally spaced rollers 55I and I52 disposedbelow the eccentric and positioned equidistantly on opposite sides ofthe axis thereof, said rollers being journalled on pin bolts i53 whichare screwed into tapped holes formed in the outer face of a flange I54.The eccentric I58 7 and rollers I5 I, I52 are arranged so that when thelow point of the eccentric is bearing on the rollers, as in Figure 5,the clutch driven member I86 is held in full engagement with the driverI35 by the spring I3I. When the high point of the eccentric I59 isresting on the rollers, however, the

outer end of the lever arm I49 is raised, causing the fork 63 to bedepressed and the driven member I96 to be pulled down out of engagementwith the driver. Two pairs of angularly spaced notches I and I56 (seeFigure 5) are formed in the rim of the eccentric I59, on the high andlow sides respectively, and these notches are adapted to receive therollers I55, E52 when the eccentric is in either of its operativepositions, providing a detent action which prevents the eccentric fromrolling out of either operative position when the controlling means isreleased.

Operation of the clutch is effected by means of a twist-grip handle I69having a cylindrical shank I6I which is journaled within a bore I52 in amember I83 pivoted at I94 on the outer end of the tiller bar 24. Thepurpose of the pivotal connection I84 is to permit the handle let toswing upwardly in the event the motor is tilted, as will be pointed outmor fully hereinafter. The shank wound strands of stainless steel wireand is capa- I5 to permit such steering movement.

ble of transmitting a considerable torque in either direction ofrotation. Thus, it is seen. that engagement or disengagement of theclutch I6 can be effected by merely turning'the twist-grip handle I66through 139, the torque thus applied being transmitted the cable I56 tothe eccentric 459 to rotate the latter and thereby swing the operatingarm I69 up or down, as the case may be.

Steering of the outboard motor is also accomplished by swinging thetiller bar 24 in the desired direction, the lower unit I3 beingpivotally supported on the transom bracket 22 for swinging movementabout the axis of the drive shaft To this end, the cylindrical topsection I5 of the shaft housing is journalled within a vertical bore H6in a tubular barrel portion H? which is integral with a bracket memberI199. The bracket member I88 extends forwardly from barrel portion II 'Iand is pivotally connected by a pin I8I to the vertical flange I82 of aclamp member I83, said clamp member I83 being formed with a downwardlyextending backing plate Hit, which bears against the back side of thetransom 29. At its front end, the clamp I83 has a downwardly extendingarm I85 terminating in a boss I86 having a threaded aperture thereinwhich receives a clamping screw I99. At its rear end, the screw I99 hasa bearing plate I9I pivotally connected thereto which is engageable withthe .front surface of the transom 29 to -secure the transom bracketthereto, while the frontend of the screw has a handle I92 by which thescrew can be turned.

During normal operation'of the outboard motor, when the boat is beingdriven straight ahead, the thrust of the propeller acting in a forwarddirection on the bottom of the lower unit produces acounterclockwisemoment on the outboard motor which is resisted byengagement of a notch I94 on the lower front end ofthe barrel portionI'I'I with a transversely extending thrust, pin I95, which extendsthrough alined holes I98 in a pair of laterally spaced flanges I97extending rearwardly from the backing .plate I84 on opposite sides ofthe barrel member I'I'I.

In order to accommodate variations in the inclination of the transom 29encountered in different makes and models of boats, the flanges I9T areprovided with a plurality of pairs of holes I96 which are arranged in anare described about the pin IBI as a center. Thus, if a particulartransom is inclined upwardly and rearwardly from the bottom of theboatand it is found that the outboard motor is tilted at an undesirableangle, the pin, I95 can be withdrawn and reinserted through any otherpair of holes I96 to bring the unit to a vertical position or to anydesired degree of angularity.

The notch I94 engages thepin I95 on the back side only thereof to takethe thrust of the propeller when the latter is driving the boatforwardly and, being open on the front side, allows the unit to tiltupwardly about the pin I8I if the propeller or skeg strikes anobstruction. Damage to the propeller and other parts of the outboardmotor is thus avoided by allowing the unit to yield and ride over theobstruction, the normaldriving position being resumed'as soon as thelower unit has cleared the obstacle. Alimit stop arm I98 projectsdownwardly and'forwardly from the front end of the bracket member I86,and is engageable with the clamp member I83 to limit the angularmovement of the outboard motor and prevent the propeller from'beingthrown out of the water if an'obstruction is hit at high speed. Thepivotal connection of the twist-grip handle I60 with the tiller bar 24,described earlier, allows the handle to fold upwardly when the unittilts and thus prevents the handle from being torn out of the operatorshand by the sudden violent angular deflection of the handle. Thisarrangement also affords protection to the operators hand against injurywhich might otherwise result if rigid tiller bar handle were to strikethe bottom of the boat or the transom. The flexible cable I66 merelybends when the tiller bar handle folds up, without disturbing theeccentric I50 or the clutch I6.

One of the features of the present outboard motor is that it can beturned 180 to drive the boat in reverse, and in this condition, with thedirection of propeller thrust reversed, the unit must be restrainedagainst tilting, as the propeller would otherwise push the bottom end ofthe lower unit up out of the water. Accordingly, we have provided ananti-tilt lock device, designated generally by the reference numeral200, which is operated automatically when the outboard motor is turnedmore than 90 in either direction from straight ahead, to lock the unitto the transom bracket.

The anti-tilt lock 200 comprises a plunger 20I which is slidablydisposed within a vertical bore 202 provided in the body of the bracketmember I80 immediately ahead of and parallel to the barrel portion Ill.The plunger 20I is yieldingly urged upwardly by a spring 203 embracingthe plunger and bearing against the bottom of a bushing 204 which ispinned or otherwise secured to the plunger. The spring 203 and bushing204 are contained within a counterbore 205 at the top end of the bore202, said spring bearing at its bottom end against the shoulder 206formed by the junction of the counterbore with the bore. The bore 202opens through the bottom of the bracket member I80, and the bottom endof the plunger MI is normally retracted into the bore so that it clearsthe thrust pin I95.

The plunger 20I is adapted to be cammed down to a position behind thepin I95, thereby locking the unit against tilting movement, and this isaccomplished by an annular cam 2l0 which engages and acts upon the topend of the plunger. The cam 2 I is formed integral with the top sectionI5 of the shaft housing and comprises a radially outward extendingflange, the bottom surface of which bears on the plunger 20!. The rearhalf 2 of the circular flange is the low side of the cam and lies in ahorizontal plane,

while the front half of the flange rises from I each side of the shafthousing in the manner of a spiral ramp to a flat high point 2 I 2 at thefront end of the housing. The cam 2I0 is so arranged and proportionedthat when the outboard motor is in the straight-ahead position shown inFigure 1, with the top end of the plunger 20I in engagement therewith,the bottom end of the plungor is fully retracted into the bore 202, andthe unit is free to tilt. When the outboard motor is turned more than90, however, the cam 2E0 depresses the plunger 20I down behind thethrust p1n I95, locking the unit to the bracket member I80.

The arrangement illustrated in Figures 6 and 7 shows an alternativeconstruction for the clutch actuating mechanism, featuring positiveengagement of the clutch it instead of the spring-loaded engagement ofthe previously described construction. In this embodiment,the eccentricI is disposed between and turns on two pairs of rollers 220 and ZZIwhich are located at the top and bottom of the eccentric. The two toprollers 220 are journalled on pin bolts 225 which are screwed intosuitable tapped holes provided in the cupshaped element 80, while thetwo bottom rollers 22! are journalled on pin bolts 226 which are screwedinto the flange I54, as in the preceding embodiment. The throw-outmechanism is initially set up so that when the eccentric I50 is turnedto bring its high point down to the bottom position, the clutch drivenmember will be just disengaged from the driver. Engagement of the clutchis then effected by turning the eccentric as far as it will turn ineither direction, at which point the driven member will be solidlyagainst the driver and further rotation of the eccentric prevented.

With this arrangement of the eccentric I50 between oppositely disposedpairs of rollers 220 and 22!, the shift lever M0 is positively swungdownwardly to engage the clutch, as well as upwardly to disengage thesame, enabling the clutch spring I32 to be dispensed with. The operationof this clutch actuating mechanism is not affected by wear of the clutchfacing I23, inasmuch as the eccentric is turned until full engagement isobtained, and a worn clutch merely requires Slightly more of a turn onthe eccentric I50 to take up'the extra clearance.

Still another embodiment of our improved clutch is illustrated in Figure10, wherein the clutch driver i and driven member I06 are substantiallythe sameas i the preceding constructions, but with an alternative clutchactuating mechanism. In this instance, the hub of the driven member I06comprises a downwardly extending cylindrical sleeve 250 whichslidablyreceives the cylindrical top end of the drive shaft E5. The hub250 is connected to the shaft I5 to drive the latter by a pin 26I whichextends diametrically through the shaft I5, and the ends of said pinbeing slidably disposed within longitudinally extending slots 252 formedin the inner surface of the hub. The slots 262 thus permit the hub 260of the driven member to slide up and down on the shaft I5, while the pin26I transmits the drive from the clutch member I06 to the shaft l5]Screwed onto the bottom end of the hub 250 is a thrust ring 253 having ashoulder 264. which bears against the bottom end of a throw-out member265 and which is also engaged by the spring I3I. The member 255 has asmooth bore 260 which serves as a journal for the hub 260, and externalthreads 210 of coarse pitch formed on the outside surface thereof whichare engaged in companionate internal threads in a stationary bushingmember 2! I. The member 2?! is screwed into a horizontal partition 2'l2formed integrally with the shaft housing top section I5. The top end ofthe throw-out member 265 is enlarged in diameter and has a plurality ofradially extending tapped holes 2'53 formed therein, and screwed intoone of said holes is the clutch lever 215 which extends forwardlythrough a transversely elongated opening 2?!) in the front wall of thehousing element E5 to a point conveniently within reach of the operator.

The clutch is actuated by swinging the lever 2M horizontally from oneside to the other, which rotates the throw-out member 265 and causes thelatter to move up or down by reason of its threaded engagement with thestationary member 2'. When the throw-out member moves down, the clutchdriven member I05 is carried down with it by the ring 255 which isscrewed onto the end of the hub 200 and which is engaged by the bot-v amno and not, in any sense restrictive on the same. To

those skilled in the art, there will occur many changes in the shape andarrangement of the several parts going to make up the machine in itsentirety, but such changes do not depart from the broad concept of theinvention defined in the appended claims.

We claim:

1. In an outboard motor having a crankshaft, and a propeller driveshaft, a clutch serially arranged between said crankshaft and said driveshaft, the combination of a lever arm operatively connected to saidclutch and pivotally supported for swinging movement betweenclutch-engaged position and clutch-disengaged position, an eccentricwheel journalled on said lever arm and e'ngageable with a stationaryelement whereby rotation of the wheelcau'ses said lever arm to move fromone of said positions to the other, and a control handle op'erativelyconnected to said eccentric wheel to turn the same.

2. In an outboard motor having a crankshaft, a propeller drive shaft,and a clutch serially arranged between said crankshaft and said driveshaft, the combination of a lever arm operatively rolling on a pair ofangularly spaced rollers disposed on one side of the center of theeccentric wheel whereby rotation of the wheel causes said lever arm tomove from one of said positions to the other, and a control handleoperatively connected to said eccentric wheel to turn the same.

3. In an outboard motor having a crankshaft, a propeller drive shaft,and means for securing said outboard motor to a boat and providing forpivotal movement of the outboard motor about a substantially verticalaxis, the combination of a clutch serially arranged between saidcrankshaft and said drive shaft, a tiller bar connected to said outboardmotor for turning the same to steer the boat, a lever arm operativelyconnected to said clutch and pivotally supported for swinging movementbetween clutch-engaged position and mg movement'between clutch-engagedposition and clutch-disengaged position, an eccentric wheel journalledon said lever arm, the peripheral edge of said wheel rolling on a pairof angularly spaced rollers journalled on said outboard motor on oneside of the center of the eccentric wheel whereby rotation of the lattercauses said arm to move from one of its positions to the other, theperiphery of said wheel being notched to receive said rollers when-thewheel is in either of its operative positions to prevent the wheel fromturning by itself, a handle journalled on said tiller bar, and aflexibletorque-transmitting cable connecting said handle to saideccentric wheel whereby the latter is turned when the handle" is turned.a

5. In an outboard motor having a crankshaft, a propeller drive shaft,and means for securing said outboard motor to a boat' and providing forpivotal movement of the outboard motor about a substantially verticalaxis, the combination of a clutchserially arranged between saidcrankshaft and said drive shaft, a tiller bar connected tosaid outboardmotor for turning the same to steer the boat, a lever armoperativelyconnected to said clutch and pivotally supported for swinging movementbetween clutch-engaged position and clutch-disengaged position, aneccentric wheel journalled on said lever arm, two pairs of angularlyspaced rollers journalled on said outboard motor on opposite sides ofthe axis of said eccentric wheel, the periphery of said wheel havingconstant rolling engagement with both pairs'of rollers, whereby rotationof said wheel causes positive'displacement of said lever arm from one ofits positions vtothe'other when the wheel is turned, and means on saidtiller-bar for turning said wheel.

6. In an outboard motor having a crankshaft, a propeller drive shaft,and a clutch serially arranged between said crankshaft and said driveshaft, the combination of a lever arm operatively connected to saidclutch and pivotally supported for swinging movement betweenclutch-engaged position and clutch-disengaged position, an eccentricwheel journalled on said'lever arm, two pairs of angularlyspaced'rollers journalled on said outboard motor on opposite sides ofthe axis of said eccentric wheel, the periphery of said wheel havingconstant rolling engagement with both pairs of rollers, whereby rotationof said wheel causes positive displacement of said'lever arm from one ofits positions to the other when I the 'wheel is turned; and a controlhandle operaclutch-disengaged position, an eccentric wheel journalled onsaid lever arm, said wheel having rolling engagement on its peripherywith at least one roller journalled on said outboard motor wherebyrotation of the wheel causes said lever arm to move from one of itspositions to the other, a handle movably mounted on said tiller bar, andmeans connecting said handle with said eccentric wheel for rotating thelatter when the handle is moved.

4. In anoutboard motor having a crankshaft, a propeller drive shaft, andmeans for securing said outboard motor to a boat and providing forpivotal movement of the outboard motor about a substantially verticalaxis, the combination of a clutch serially arranged between saidcrankshaft and said drive shaft, a tiller bar connected .to saidoutboard motor for turning the same to steer the boat, a lever armoperatively connected to said clutch and pivotally supported forswingtively "connected to said eccentric wheel for turning the same.

7In an outboard motor having a crankshaft, a propeller drive shaftcoaxial with the crankshaft, and a clutch serially arranged between saidcrankshaft and said drive shaft, said clutch comprising arr-invertedcup-shaped driver having a non-"rotatable sliding connection with saidcrankshaft, a companionate driven member slidabl and non-rota-tablyconnected withsaid drive shaft, said driven member being disposed withinand engaging the inner surface ofsaid driver, an anti-friction radialand thrust bearing having one race thereof fixedly mounted on said driveshaft, said driver being fixedly mounted on the other race of saidbearing, a spring bearing at one end on said driven member and urgingthe latter into engagement with said driver, said spring bearing at itsother against a shoulder on said drive shaft to transmit its thrustthereto, and means engageable with said driven member to move the latterout of engagement with said Number driver against the thrust of saidspring. 1,733,361 ELDON M. WILSON. 1,857,636 LATHAM POLLOCK. 1,933,481 52,059,935 REFERENCES CITED 2,09 04. The following references are ofrecord in the 2,155,112 file of this patent: UNITED STATES PATENTS 102,342,446 Number Name Date 413,569 Sherman Oct. 22, 1889 1,371,251Larson Mar. 15, 1921 Number 1,382,955 Clementson June 28, 1921 282,0581,683,893 Irgens Sept. 11, 1928 15 Name Date .Rice Oct. 29, 1929 I-IeideMay 10, 1932 Mathias Oct. 31, 1933 Eason Nov. 3, 1936 Bowden Sept..7,1937 Anderson Apr. 18, 1939 Contoni Aug. 26, 1941 Blankshain Oct. 21,1941 Beaven Feb. 22, 1944 FOREIGN PATENTS Country Date Germany Feb. 12,1915

